I originally had Windows XP on my computer. Then I decided to download Ubuntu 12.04. I didn't use any CDs or USBs or anything. I did not know that in doing so I wouldn't have access to any of my files. If I switch back to XP will my files still be there? If so, how do I switch back?

If you mean you used wubi, then yes, your files should still be there. If you used a live cd/dvd/usb, It's possible you could have deleted XP. Does it show XP at the boot menu? If so, navigating to it and pressing enter should boot your old OS. If XP doesn't appear in the boot menu, then most likely you're out of luck.

Since I did find my files I don't need to switch back to XP anymore but I still want to know how just in case. Where is the boot menu, exactly? Sorry if this question seems stupid. I knew Linux was for experienced users but it was so tempting.
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CordenneJun 24 '12 at 6:05

@Cordenne Linux isn't just for experienced users. Ubuntu was designed in a way that everyone can use. The First Day of using it can be hard, but you will learn more as you go on.
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Emerson HsiehJun 25 '12 at 22:37

BTW If you can't see the boot menu, hold Shift when you start the computer. Or you can read my answer here to do a permanent Fix.
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Emerson HsiehJun 25 '12 at 22:39

I guess you mean you use wubi installation method. i.e Install Ubuntu inside Windows as a seperate application. In this case, Windows should not be deleted. You can easily access Windows at boot menu. Boot menu is a menu which provide you to choose from existing OS to boot.

If I switch back to XP will my files still be there?

If you are referring to boot into the XP, yes, you will find your files there. But if you are referring to Installing XP again by removing Ubuntu installation, which probably be installed inside the Windows. You will not get your file, if you install XP again in the same partition.

You can uninstall Ubuntu (if you used wubi method) just as like as you uninstall any other program in XP. Going to control-center --> Add/Remove Program